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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
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To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

16162 results found.

  1. ZTF23aaoohpy/AT2023lcr: LBT observations
  2. GRB230628E: VLT optical identification of afterglow candidate
  3. GRB 230628E: LCOGT Optical Upper Limit
  4. LIGO/Virgo/KAGRA S230516az: GOTO candidate counterpart GOTO23hu ruled out by Zwicky Transient Facility observations
  5. ZTF23aaoohpy /AT2023lcr: TNG NIR detection
  6. LIGO/Virgo/KAGRA S230627c: ATLAS information on the ZTF candidates
  7. ZTF23aaoohpy/AT2023lcr: further SAO RAS observations
  8. ATLAS23msn/ZTF23aaoohpy/AT2023lcr: Zeiss-1000 of Koshka observatory optical observations
  9. MAXI GRB 230623A: MASTER optical observations
  10. ZTF23aaoohpy/AT2023lcr: SAO RAS observations
  11. AT2023lcr: VLA radio detection
  12. ZTF23aaoohpy/AT2023lcr: Montarrenti Observatory optical observations
  13. ZTF23aaoohpy (AT2023lcr/ATLAS23msn): Swift/UVOT detection
  14. ZTF23aaoohpy/AT2023lc: Mondy optical observations
  15. AT2023lcr: Neil Gehrels Swift Observatory X-ray detection
  16. ZTF23aaoohpy/AT2023lcr: Keck/LRIS spectroscopy and redshift
  17. ZTF23aaoohpy/AT2023lcr: Xinglong-2.16m optical observations
  18. ZTF23aaoohpy/AT2023lcr: Liverpool Telescope detection
  19. ZTF23aaoohpy/AT2023lcr: OHP/T193 and OHP/T120 optical follow-up observations
  20. ZTF23aaoohpy/AT2023lcr: GOTO early optical observations and constraint
  21. GRB 230618A: Swift/UVOT Upper Limits
  22. GRB 230618A: KAIT Optical Observations
  23. GRB230618A: LCOGT Optical Observations
  24. LIGO/Virgo/KAGRA S230615az: T80S Search and Candidate Counterpart Identification
  25. LIGO/Virgo/KAGRA S230615az: Non-Detections of GROWTH-India Candidates from GECKO Optical Observations
  26. LIGO/Virgo/KAGRA S230615az: GOTO candidate counterparts
  27. GRB 230606A: LCOGT Optical Observations
  28. ZTF23aamxeqf/AT2023jxk: 1.3m DFOT Optical upper limit
  29. ZTF and GIT Observations of the Candidate Optical Afterglow AT2023jxk
  30. GRB 230606A: Gaoyazi/GOT optical upper limit
  31. GRB 230606A: BOOTES-5/JGT optical upper limit
  32. GRB 230606A: Swift/UVOT Upper Limits
  33. LIGO/Virgo/KAGRA S230518h: TESS observations of the localization region
  34. LIGO/Virgo/KAGRA S230521k: MASTER new OT discovery
  35. LIGO/Virgo/KAGRA S230521k: Additional candidates from Zwicky Transient Facility
  36. LIGO/Virgo/KAGRA S230518h: ATCA follow-up of candidate counterparts
  37. LIGO/Virgo/KAGRA S230518h: GECKO tiling observations with KMTNet
  38. LIGO/Virgo/KAGRA S230518h: ATLAS observations of the skymap
  39. LIGO/Virgo/KAGRA S230518h: Swope Search and Candidate Counterpart Identification
  40. Improved IPN triangulation of GRB 230512A
  41. GRB 230512A: Nanshan/NEXT non-detection of GRB afterglow candidate
  42. GRB 230512A: Liverpool Telescope observations
  43. GRB 230512A: GIT non detection of afterglow candidate
  44. GRB 230512A: Kitab possible afterglow candidate
  45. GRB 230510A: OHP/T193 and OHP/T120 optical observations
  46. GRB 230512A: GIT optical follow-up ZTF candidates
  47. GRB 230510A: GIT optical upper limits
  48. GRB 230510A: LCOGT Optical Upper Limit
  49. GRB 230510A: Gaoyazi/GOT optical upper limit
  50. GRB 230510A: Nanshan/NEXT optical afterglow detection
  51. GRB 230506B: Swift/UVOT further analysis
  52. GRB 230506C: SAO RAS optical observations
  53. GRB 230307A: JWST second-epoch observations
  54. GRB 230506C: spectro-imaging observations of the optical afterglow with T193-OHP
  55. GRB 230506B: LCOGT Optical Upper Limits
  56. GRB 230506C: Swift/UVOT Upper Limits
  57. GRB 230506C: NUTTelA-TAO / BSTI Early Optical Limits
  58. GRB 230506B: MASTER optical observations
  59. GRB 230420A: Mondy optical afterglow detection, TSHAO, CrAO optical upper limit
  60. GRB 230420A: AROMA-N Optical Upper Limit
  61. GRB 230427A: NOT optical upper limit
  62. GRB 230427A: TSHAO, SAO RAS, AbAO optical upper limit
  63. GRB 230427A: Gaoyazi/GOT optical upper limit
  64. GRB 230427A: Nanshan/HMT optical upper limit
  65. GRB 230427A: Osservatorio Astronomico Nastro verde upper limit
  66. GRB 230427A: GIT optical upper limit
  67. GRB 230427A: Bassano Bresciano Observatory upper limit
  68. GRB 230427A: GMG upper limit
  69. GRB 230427A : OHP/T193 optical upper limit
  70. GRB 230427A: BOOTES-5/JGT afterglow detection
  71. GRB 230426A: MASTER OT J023135.16-792104.8 optical counterpart discovery
  72. GRB 230427A: MITSuME Akeno optical upper limits
  73. GRB 230427A: Swift detection of a burst with an optical counterpart
  74. GRB 230423A: Swift/UVOT Upper Limits
  75. GRB 230420A: Lowell Discovery Telescope Optical Detection
  76. GRB 230420A: Swift/UVOT Upper Limits
  77. GRB230420A: VLT optical observation
  78. GRB 230420A: MITSuME Akeno optical observation
  79. GRB 230420A: NOT optical afterglow confirmation
  80. GRB 230420A: Gaoyazi/GOT optical upper limit
  81. GRB 230420A: BOOTES-5/JGT optical afterglow detection
  82. GRB 230420A: LCOGT Optical Upper Limit
  83. GRB230414B: VIRT Optical Upper Limit
  84. GRB 230414B: Nickel and KAIT telescope optical observations
  85. GRB 230414B: Swift/UVOT Detection
  86. GRB 230414B: Osservatorio Astronomico Nastro Verde - Sorrento: optical observations
  87. VIRT optical transient detection
  88. GRB 230414B: 3.6m DOT Optical observations, slow decay at early epochs
  89. GRB 230307A: iTelescope optical upper limit (likely)
  90. GRB 230414B: Montarrenti Observatory late time optical afterglow detection
  91. GRB 230414B: Lulin 40cm-SLT optical limit
  92. GRB 230414B: Bassano Bresciano Observatory optical observations
  93. GRB 230414B: AbAO optical observations
  94. GRB 230409B: 3.6m DOT near-infrared detection, afterglow confirmation
  95. GRB 230414B: Dabancheng/GHOST optical observations
  96. GRB 230414B: slow optical light curve decay
  97. GRB 230414B: SAO RAS optical observations
  98. GRB 230414B: 1.3m DFOT Optical observations
  99. GRB 230414B (correction GRB name in the GCN 33615): Mondy optical afterglow candidate
  100. GRB 230414B: Nanshan/HMT optical afterglow detection

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